I just saw the most recent tour of My Fair Lady at the Kennedy Center in DC. I got to go on a backstage tour of the show and noticed the wagons they use to move scenes on and off. Naturally they used a tracked deck with a cable system to move the wagons, but I couldn't figure out what kind of wheels they were using. Of course we weren't supposed to touch anything, but as the group moved forward I couldn't resist. I lagged behind and gave the thing a shove. Needless to say it sailed like a ghost 7 or 8 feet across the stage before the cable jerked it to a stop (and I probably fouled it up in the motor too But I have no idea how they got that thing to be so silent and so low to the ground (it was 2" max off the deck) Anyone know how to do this? Air cushion? Uber soft rubber wheels? Mag Lev? The Force?